2-Oxobutyrate (2-OBA) is an important intermediate with many applications in the drug and chemical industries. L-Threonine, an industrial fermentation product, could be used as a suitable starting material for the 2-OBA production. In this study, whole cells of Pseudomonas stutzeri SDM were confirmed to possess a good ability to convert L-threonine into 2-OBA. The bioconversion conditions were optimized for the 2-OBA production from L-threonine. Using 9.2 g dry cell weight l(-1) of whole cells of strain SDM as biocatalyst, the biocatalytic process produced 2-OBA at a high concentration (25.6 g l(-1)) with a high molar conversion rate (99.6%) at 6 h from 30 g l(-1) of L-threonine. (C) 2012 Elsevier Ltd. All rights reserved,